Joint for folding rules.



F. BUCK.

JOINT FOB FOLDING RULES.

ArPmcAioN FILED AuG.2s.1918.

l 26,52 Patented Dec. 3, 1918.

rann BUCK, or sAGINAw, MICHIGAN, AssIGNoa ro THE LIIFKIN RULE COMPANY, `or sAGINAw, MICHIGAN, A conPonArIoN or MICHIGAN.

0 JOINT FOR FOLDING RULES.

Specification of Letters Eatent.`

Patenten nec. a, irais.

i Application filed August 26, 1918. Serial No. 251,467.

To all whom t may concern:

Beit known that I, FRED Buon, a citizen ofthe United States and a resident of Saginaw, county of Saginaw, and State of Michigan, have invented; a newand useful Improvement in Joints i'or Folding Rules, of which the following is a specification, the principle of the invention being herein eX- plained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

The present invention, relating, as indicated, to joints for Jfolding rules, is directed to an improved hinge member for joining two adjacent sections of the folding carpenters rule which is commonly known as a boxwood rule, and which is very generally used. One of the objects 'of the invention is the provision of a hinge which will be practically self-fastening in the two adjacent sections of the rule, and will require the use of but two oi the pins, screws or other parts for maintaining it in place. To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description setdforth in detail certain mechanism embodying the invention, such dis closed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings Figure l is a perspective view ci. two adjacent sections of a carpeirtei"s rule assembled with my improved hinge; F ig. 2 is a section on the line 2*2, Fig. 3; Fig. 3 is a section on the line 3-3, Fig. 2; and Fig. 4lis a longitudinal section through the central hinge of a four-section -carp'enters rule, showing a slightlyT different type of hinge for the central sections.

In Fig. 2 I have shownfa perspective view of a rule of the folding type, which is par c tially open to show the hinge between the adjacent section 10. The hinge member consists of a plurality of hollow portions l, set about, and held together by, a pin 2 provided with two sets of parallel plates 3 eX- tending at rightangles to the axis of the member l, with all of the plates 3 lying in parallel planes. Each member of each pair of these plates 3 is formed at one end with a circular apertured portion 4 extending about the pin 2 between the sections of the member l, and ybeing snugly held inthe memberl so that the rictional contact of the plates against each other, and against the member l, is suilicient to maintain the rule in any given position against accidental movement.

The sections or portions of the member l are of substantially the same length and the plates 3 held between the sections are inserted under pressure into narrow slots cut into the adjacent ends of two sections of the rule, the thickness of the plates being the same as the width of the slots, so that there is a considerable frictional grip vbetween the sections ci the rule and the plates. This grip is made secure by the formation of a series of saw teeth 5 on the end of each of the plates 3. 'Ihcse saw teeth are forced into the wood at the bottom 'of each of the grooves cut in the rule sections, and I have found that this engagement is suii'iciently secure and firm so that it is necessary to drill but two holes transversely of the rule section and of the plates 3 for the insertion of pins 15, while heretofore at least four such pins have been considered essential in holding the adjacent sections in engagement with the hinged members. The elimination of the necessity for drilling two holes at the end of each rule section and the inserting therein of pins, which pass through, not only the wood of the rule, but also the metal of the hinge plates, eiiects a considerable saving in the cost ci manufacturing and assembling this type of rules. Not only arekseveral operations avoided in the making of each rule and the rules are :found to be oi' sufficient strength to withstand the common usage to which they are put.

In Fig. there are shown two central sections l1 of a carpenters rule, which are proF vided with longitudinal horizontal slots or recesses therein, into which may be snugly ittted projecting plates l2 pivotally attached to each other by means of a pin 13, and provided with projecting teeth 14 adapted to be inserted and to engage the wood a-t the bottom of the recess. The hold ing action of this hinge is similar to the hold-ing action of the hinge shown in the preceding lignres, this last hinge being constructed, however, to permit of pivoting of the connected adjacent sections in the plane of the greatest transverse dimension 'of these sections instead of in a plane at right angles to these as in the case of hinges of Figs. 1, 2 and 3.

Other modes of applying the principle o't my invention may be employedk instead of the one explained, change being` made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention 1. In a hinge for rules comprising tWo pivotally connected members, each being provided With parallel plates adapted to be 15 inserted in slots in the end of a rule section, said plates having sharpened engaging ends.

2. In a hinge for rules comprising two pivotally connected members, each being provided with parallel platesl adapted to bc 20 inserted in slots in the end of a rule section, said plates being provided With a plurality of sharpened points on their inserted ends.

Signed by me, this 16th day of August, 1918.

FRED BUCK.

Copies of this patent may be obtained for ve cents each, by addressing the "Commissioner of latents. Washington, D. C. 

